Telephone-switchboard



' UNITED STATES PATENT OFFICE.

HENRY M. FISK, or AUSTIN, ILLINOIS.

-TELEP'HONE-SWITCHBOARD.

SPECIFICATION forming part of Letters Patent No. 559,348, dated April 28, 1896.

Application filed May 27, 1895; Se'riel llo. 550,898. (N0 model.)

To all whom it may concern:

Beit known that I, HENRY M. FISK, a citizen of the United States of America, residing at Austin, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Switchboards for Telephone-Exchanges, of which the following is a full,- clear, concise, and exact description, ref erence being had to the accompanying drawings, forming a part of this specification.

My invention relates to subscribers signals in combination with a connecting or switching device commonly designated a springjack. I

Figure 1 represents a side sectional view of drop,showin g plug inserted and drop restored. Fig. 2 represents combination spring-J a'ck an (I plug, showing manner of connecting cords.

Fig. 3 represents drop in a fallen position,

also end view of magnet, showing pivoting of armature and means of connecting combination-plu g with extensions of line. Fig. 4 represents an end view of magnet, showing means of attaching and adjusting the same. Fig. 5 represents a side and top view of extension of line from back to front of board.

In Fig. 1, a b 0 cl represent anelectromag-i net, of which a is a winding of fine wire of u any desired resistance. 1) is an iron core provided at the back end with a threaded portion I). c is a brass or other non-magnetic metal plate provided with lugs and screws for pivoting armature d, also bent out at top endto a point slightly beyond end of core to prevent armature from sticking to core after current is shut oif. e represents shutter or drop in normal position with top of armature (Z under lower corner supporting the same. ff represent adjusting-nuts bearing on back plate h and means for the proper adjustment of armature to shutter or drop. g 9 represent means for extending subscribers circuit from back to front of board, and more fully represented in Fig. 5. 11 represents insulated handle portion of. combination plug and spring-jack. j represents one of the sides of combination plug and spring-jack made of some conducting material andprovided with means of connection with extension g and one side of cord 75.

In Fig. 2, 'i represents an insulating mate-' rial forming part of combination plug and spring-jack, provided with an extension curving upward for restoring shutter or drop to its normal position. j j represent metallic strips provided with means of connection with extension-cords'k k and also for connection to extension of lines on switehboard.-

In Fig. 3, e represents shutter or drop in a fallenpositionand indicating a call from subscriber of same number. 9 g gg g g repre sent end View of extensions of line, showing flexible cord. 1). represents top view of extension, showing form of depression 0.

. The operation of my invention is as follows: Either by connecting up subscribers line one side to one extension g, Fig. 1, and the other side to ground and connecting other extension to ground, or by what is known as common return system, or a metallic circuit, you have the following results: In sending an electric current through line it passes through winding and energizes magnet, causing armature d to be attracted toward end of core 6, re-[ leasing the shutter or drop 6, allowing it to fall, as in left-hand portion of Fig. 3, which notifies, operator, who will insert the combination plug and spring-jack and restore drop to normal position and extend circuit to flexible cord for connection to number desired.

Having thus fully described my invention, I claim asnew and desire to secure by Letters Patent- The combination. in a telephone-switchboard of an electromagnet and a drop or a shutter in front of it with connecting or extension points in front of the shutter, and a thin plug attached to a flexible cord and made to look into the connectors or extension-points substantially as specified;

Witnesses:

ARTHUR W. FIsK, KIMBALL H. CorrLE.

HENRY M. FISK. I 

